Fire and temperature alarm or indicator.



No. 891,743. PATENTED JUNE 23, 1908.

G; L. SMITH;

FIRE AND TEMPERATURE ALARM 0R INDICATOR. APPLICATION FILED MAR.19, 1908.

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G. L. SMITH.

FIRE AND TEMPERATURE ALARM 0R INDICATOR. AYPLIOATION FILED MAR.19, 1908.

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No. 891,743. PATENTED JUNE 23, 1908.

GEORGE LAWRENCE SMITH, OF ABERDEEN SGOTLAND.

FIRE AND TEMPERATURE ALARM OR INDICATOR.

Specification of Letters Patent.

Patented June 28, 1908.

Application filed March 19, 1908. Serial No.'422,147.

T 0 all whom/it may concern:

Be it known that I, GEORGE LAWRENCE SMITH, a subject of the King ofGreat'Britain, residing at Aberdeen, Scotland, have invented certain newand useful Improvements -in Fire and Temperature Alarms or Indicators,and of which the following is a specification.

In the specification of my United States Patent No. 850681 dated 16thApril 1907, I have described a fire and temperature alarm orindicatorapparatus, operating by pneumatic expansion, and in which a metal tubeof small diameter containing airat atmospheric pressure is employedextending through a distance around a place where a sudden rise oftemperature is to be indicated, the said tube communicating with aclosed expansible chamber at one end, a movement produced in the latterchamber by air expansion due to the sudden rise of temperature beingadapted to make or break an electric circuit for the purpose of soundingan alarm the opposite end of the tube of this apparatus is closed, andan air vent is provided by which the air may pass to or from the tube tothe atmosphere nary variations of temperature, but upon a sudden rise oftemperature, the chamber is expanded and operates an alarm.

Now the present invention refers to improvements upon the inventiondescribed in my prior patent specification aforesaid, the object beingto so construct the apparatus that not only shall an alarm be given upona upon ordisudden and unusual rise of temperature, but

in addition to this, the object of the present invention is to providethat another signal shall "be given should the small diameter metaltube, extending around the place to be protected, become fractured orbroken by accident or otherwise, so that there is a free escape of airtherefrom other than by the leak or throttled passage provided. Toeffect this object, the tube extending around the premises to beprotected, is closed at one end and at the other communicates, as in thebefore-mentioned apparatus, with an exansible chamber,- and there is anair vent or eak communicating with the passage of the tube which permitsair to pass slowly to and from said tube. The said air vent communicateswith a chamber containing air or gas at a pressure difleringfrom that ofthe atmosphere", and consequently normally the pressure in the pressurechamber is equal to to escape by the art. nicates, by the passage 10,with the tub 11 the pressure in the tube by reason of the communicatingvent. By reason of this arrangement, upon a sudden and'unusual rise of.temperature in the place to be protected, the air expands in the metaltube too rapidly said air vent, and conse 'uently the expansibletube-chamber is expan ed, an electric circuit thereby completed, and afire alarm given, whereas should the metal protecting tube be damagedsayfracturedthe .pressure air would escape, the expansible tube-chamberwould contract, another electric circuit would be completed, and anothersignal'given indicating that the apparatus was not in working order,that is, what I term a trouble call would be given. I

In the accompanying drawings a simple example of construction is shownat Figure 1 invertical section, and by the description hereafter ivenrelating to this figure, the Working of the a paratus will be readilyunderstood, while Fig. 2 shows, also in vertical section, a preferredform of construction of the apparatus, Fig. 3 being a detail view of avalve employed in the construction at Fig. 2.

Referrm to Fig. 1 of the drawings, I prochamber or reservoir 2communicating by two assages 3, 4 respectively with two chambers 5, 6.The side walls of the chambers 5, 6 are composed of three flexiblediaphragms, 'i. e. a central dia hragm 7 and two outer diaphragms 8, 9,t e peripheries of these dia hragms being secured to the body part 1 ofthe apparatus in any suitable or convenient manner, the drawing beingsufficient to render the construction of the ap aratus sufficientlyclear for persons skille in One of these chambers 6 comg uwhich passesaround a room or other place to be protected, and the said chamber 6also communicates, by a passage 12 with what is termed a leak in myprevious patent s ecification; the leak consists of a screw 13 aving avalve-likehead fitted with a porous washer l4, and the valve-like headcovers the passage 12 and also covers the passage 15 communicatin withthe chamber 5. Thus instead of the oak from the tube 11 communicatingdirect with the atmos here, it communicates, in this case, with thechamber 5 which normally contains air (or gas) pressure equal to the air(or gas) pressure in the chamber 6 and in the tube.

eyond this, the-chamber 5 can be caused to vide a bory part 1 containinga pressure e interior of phragm 9 .voir 2 to any "pressure chamcommunicatewith the tube-chamber 6 by means of the passage 4, which isfitted with a valve 16 by which the said passage 4 can be permanently"closed when desired. 17 is an air inlet valve of any ordinary or wellknown construction through which air can be pumped by an suitable forcepump into the pressure cham er.

The central flexible diaphragm 7 is connected with one pole of thebattery 17*, and hasa central contact 18' on each-of its sides, one inthe tube-chamber .6 and the other in the chamber 5. The outer diaphragm8 has a contact 19 electrically connected with the fire or alarmcircuit, while the outer diaof the tube-chamber 6 has a contact 20connected with the trouble cirwit; and beyond this, there are adjustmentscrews 21 carried by stationary bridges'23 which limit .the outwardmovement of the diaphragms 8 and 9 and which can be brought to act uponthe external faces of the outer diaphragms to adjust the contacts whichthe carry as regards distances from the central diaphragm.

The air is pumped i to the, ressure reserdeslred pressure aboveatmospheric pressure, and at the same time is admitted by the valvef16and the by-pass 4 into the tube-chamber 6-, so that the pressure in thetube-chamber 6 and in the pressure.

chamber 5 are equalized, and then the bypass passage 4 is hermeticallyclosed. When this is done, the central diaphragm 7 will reand theouterheld distended main in its normal position, diaphragms 8, 9, willbe against their adjustment screws and with their contact'pointsaway-from the central diaphragm, whereas if no pressure existed inchambers, the outer diaphragmcontact points would close onto thecentral. dia-' phra m.

en an ordinary or. radual rise of temerature occurs in the ace throughwhich the tube 11 passes an so pressure is increased inthe tube, the airwill raduallyass through the leak (which pre erably is orouswasher) andinto the er, and so the pressure in the pressure chamber and in thetube-chamber would still remain equal and no ca will be made When theressure, however, is suddenly. increased in t e tube by a fire for notpass through the and consequently tted with a leak sufliciently rapidly,the central diaphragm will contact with the contact pin 19 carried'bythe dia hragm closing the pressure chamber, and a Ere callwould be made.

In case of any damage to the apparatus, such for instance as someaccident causing a leakage b fracture of the tube, the pressure in thetu e chamber would fall rapidly, be-

cause the be forced over into leak by which the tube commumcatesf withthe pressure chamber would notsupply pass away through the leak andescapeat the su posedfault in the tubing 1 1, and then-the 'ot ierouterdiaphragm 8 would close down into contact with the central diaphragm andbring the fire circuit also into operation. .shown at Figs. 2 and 3,thepressure chamber 24 is formed by an air-ti ht closed box .whichcontains an expansible case 25 substantially equivalent to thetube-chamber previously described; this expansible case 25 communicates,by a passage 26, with the tube 11 passing around the room or otherplace, but otherwise the said expansible case 25 is closed. The passage26 is also provided'with a leak, governed by a screw 27, located withinthe pressure chamber. Within thesaid chamber 24 is mounted an adjustablebar 28 of insulating material carrying electrical contacts 29 and 30,and the expansible case 25 carries a contact 31 located between theconpipe 11 passes to a control ing valve located in any suitableposition, as for instance fixed to the pressure chamber as shown." Inthe casing or frame of this valve there is a fpassage 32 from the tube11 to theyalve ace, and there'is also a passage 33 to the valve facecommunicating with-a pipe to a reservoir 40 containing pressure air orgas.

The valve illustrated by way of exam le consists of a revoluble disk 35operated bya handle 36 connected with disk, and the face of the disk 35hearing on the valve face .is shown at Fig. 3; it is formed witha,;groove 37,'and the positions of the'passages 32 and 33 are indicatedby dotted lines, while the dotted lines 38 indlcate a groove formed inthe face "of the valve case.

'When the ha die 36 and disk 35 are in the cannot pass by way of thepassage'33, nor can air escape from the pressure-chamber 24, through thevalve by way of the communicating passage 39. When the handle'36 isrocked-1n the direction of the'arrow, Fig. 3, pressure air will bepermitted to pass by the to t e passage 32 and to the tube .11, andsimultaneou sly by the groove air pressure 1n the tube 11 and in thecharm The banfrom the pressure chamber 5 would gradually tacts 29 and30. The op osite end of the 34 leadingthe spindle of the positionshownin the drawings, pressure air ber 24 will be equal, and no movement ofthe. j,

In the preferred form of construction-g pas age 33 and the groove 37 ofthe disk 35 38 (Fig.- 3) in the case, to the pressure chamber24, so thatthe",

dle 3.6 is then again brought to the normal position shown in thedrawings, closing the passages 32 and 33.

Should a sudden rise of tem erature occur, the expansion of air in thetu e 11 will then act in the interior of the expansible case 25, and thecontact 31 will be brought against the contact 29, and by theelectricconnections, for instance such as indicated, the fire alarm will begiven. On the other hand, should damage happen tie pressure air escape,the expansible chamber 25 would contract and the electrical contact 31be brought against the contact 30,

and a trouble call be given through the electrical connectionsindicated. be a gradual riseof temperature, the slow expansion of air inthe tube 11 would pass by the leak screw 27 to the pressure chamber 24and equalize the pressure,

When the handle 33 and the disk are turned in the opposite direction tothe arrow (Fig. 3) pressure is then admitted by the pas sage 33 to thepassage 32 only, and thereby to the tube 11, and thus a test alarm canbe given in order to definitely ascertain that the apparatus is inperfect working order.

What I claim as my invention and desire to secure by patent is 1. Infire and temperature alarms; the combination with a small diameter metaltube closed at one end, an ex ansible chamber with the interior of whicthe open end of said tube communicates, said tube having a vent forermitting air to pass slowly to and from said tube and expansiblechamber; of a pressure chamber with the interior of which said air ventcommunicates, the movable diaphragm of said-expansible chamber beingalso located insaid pressure chamber, means for sup lying air atpressure to said pressure cham er, to said tube and to the mterior ofsaid expansible chamber, an electric battery, two electric alarmdevices, and electric contacts and connections calculated to completeone electric circuit and sound one alarm device u on the ex ansion ofthe expansible chamher by su den rise of temperature expanding the airin said tube, and

to sound the other alarm device upon pressure air escaping from saidtube and the interior of said ex ansible chamber to the outeratmosphere, su stantially as set forth.

2. In fire and temperature alarms; the combination with a small diametermetal tube closed at one end, an ex ansible chamber with the interior ofwhic the open end of said tube communicates, said tube having a vent forpermitting air to pass slowly to and from said tube and expansiblechamber; of an air-tight ressure chamber within which said expansi lechamber and said vent are located, means for supplying airpressure tosaid pressure chamber and to the interior of said expansible chamber'and said tube,

to the tube 11 and,

Should there said air pressure being normally equalized through saidvent, two insulate stationary electric contacts located at a distanceapart in said pressure chamber, an electric contact mounted on themovable diaphragm of said expansible chamber and extendin between saidtwo stationary contacts, two e ectrically olperated alarm devices, anelectric battery, e ectric connections calculated to operate one of saidalarm devices when the expansible chamber is expanded by sudden rise oftemperature acting upon the tube causing the electric contact carried bysaid expansible chamber to contact with one of the stationary contacts,and electric connections to cause the other alarm device to operate whenthe contact carried by the exp'ansible chamber contacts with the otherstationary contact, substantially as set forth.

3. In fire and temperature alarms; the combination with a small diametermetal tube closed at one end, an expansible chamber with the interior ofwhichthe open end of said tube communicates, said tube having a vent forpermitting air to pass slowly to and from said tube and expansiblechamber; of an airtight pressure chamber within which said vent andexpansible chamber are located, means for su plying air at pressure tosaid pressure cham er and to the interior of said expansible chamber andsaid tube said air pressure being normall equalized through said vent,two insulate stationary electric contacts located at a distance apart, abar of insulating material fixed to the walls of said pressure chamberto carry said stationary contacts, an electric contact mounted upon themovable diaphragm of said expansible chamber and extending between saidtwo stationary contacts, twd electrically operated alarm devices, anelectric battery, an electric conductor connecting one pole of saidbattery to one pole of each of said alarm devices, an electric conductorfrom the other pole of one of said alarm devices to one of saidstationary contacts, and an electric conductor from the other pole ofthe second alarm device to the other stationary contact, and an electricconductor from the other ole of said battery to the contact carried bythe movable diaphragm of said ex ansible chamber in order that when said0 amber is expanded by the action of heat on said tube, its contactshall make connection with one of said stationary contacts and sound afire alarm by one of said alarm devices, while when said tube isfractured and said expansible chamber contracts, the contact of thelatter shall make connec- 'tion with the other stationary contact andsound the other alarm device, substantially as set forth. o I

4. In fire and temperature alarms; the combination with a small diametermetal tube closed at one end, an expanslible chama vent for permittingair to pass slowly) located, a reservoir forcontaining air at a tubeconnecting said reservoir pressure,

means for conwith said pressure chamber,

trolling the supply of said pressure air from said reservoir to saidpressure chamber, two

insulated stationary electric contacts located at a distance apart insaid pressure chamber, an electric contact mounted on the movablediaphragm of said expansible chamber and extending between said twostationary contacts, two electrically operated alarm devices, anelectric battery, electric connections calculated to operate one of saidalarm devices'when the expansible chamber is expanded by sudden riseoftemperature contact carried-by said expansible chamber to contact withone of the stationary contacts, andjelectric connections to causetheother alarm device to operate when the contact carried by the expansiblechamber contacts with the other stationary contact, substantially as setforth.

5. In fire and temperature alarms; the combination with a metal tube ofsmall diameter having a corres ondingly small bore containing air andclose at one end, a closed exp'ansiblephamber with which the other openend of said tube communicates, said tube having a vent for acting uponthe, tube causing the electric,

slowly to and from the ore of the tube upon a gradual and ordinaryvariation of temperature, and means for re ulating said vent; of anair-ti ht pressure 0 amber within which the sai expansible chamber andsaid vent are located, means for supplying air pressure to said pressurechamber and to the interior of said expansible chamber and said tubesaid air pressure being normally equalized through said vent, twoinsulated stationary electric contacts located at a distance apart insaid pressure chamber, an electric contact mounted on the movablediaphragm of said expansible chamber and extending between said twostationary contacts, two electrically operated alarm devices, anelectric battery, electric connections calculated to operate one of saidalarm devices when the expansible chamber is expanded by sudden rise oftem erature acting upon the tube causing the e ectric contact carried bythe expansible chamber to contact with one of the stationary contacts,and electric connections to cause the other? alarm device to operatewhen the contact carried by the expansible chamber contacts with theother stationary contact, substantially as set forth.

Inwitness whereof I have hereunto set ermitting air to pass my hand inthe'presence of two witnesses GEORGE LAWRENCE SMITH. Witnesses:

WM. SHERMAN- CARsoN,

ARTHUR J. SMITH.

